LEARNING OBJECTIVES...B. Take the help of y our teacher and pr epare a PowerPoint presentation on t...

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IntroductionComputer is an electronic device capable of solving problems by accepting data,

performing operations on the data, and giving the result. Before going into the

details, let us revise some important terms learnt in the previous classes.

InputInput is the raw data given to the computer using input devices like keyboard,

mouse, scanner, etc.

Just as you put fruits in

a juicer, similarly, you

input the raw data onto

a computer (Fig. 1.1).

1 ComputerKnow Your

You will learn about:

1. Input–Process–Output data flow diagram

2. network and Internet concepts

LEARNING OBJECTIVES

Fig. 1.1 Input process

5 + 4 =

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ProcessThe raw data is manipulated to generate

information by performing certain

operations using the computer’s

processing device, that is, Central

Processing Unit. It is similar to the

processing of fruits in the juicer

(Fig. 1.2).

OutputThe information generated is known as

output. It is given to the outside world

with the help of output devices like

printer, monitor, etc. It is similar to the

juice served in glasses, after processing

(Fig. 1.3).

Input–Process–Output Cycle (IPO Cycle)The three terms, that is, input, process and output are interrelated. The information

flows from the input device to the processing device and then to the output device.

Sometimes the result generated acts as an input for the next stage of data flow.

Thus, this whole flow of information follows a cycle which is known as

Input–Process–Output Cycle.

The information flow

aims to present the

information in a

user-friendly way

(Fig. 1.4).

Fig. 1.4 Input–Process–Output Cycle

INPUT PROCESS

STORAGE

OUTPUT

Fig. 1.3 Output process

Fig. 1.2 Processing of inputs

5 + 4 =






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Fig. 1.5 Storage device

Fig. 1.7 Generating a report card

Information often needs to be kept safe for later use. This information may be stored in storage devices like floppy disk, compact disc, hard disk, flash drive, memory cards, etc. (Fig. 1.5).

Let us also study the IPO cycle

in the form of the following

examples.

Adding two numbers1. Input: Two numbers to be added, are given

to the computer using an input device.

2. Process: Addition operation is performed on

these two numbers.

3. Output: Result is displayed on the screen

(Fig. 1.6).

Generating a report card1. Input: The marks of all subjects

entered in the computer.

2. Process: Percentage or grades

calculated and report card

generated in a specific format.

3. Output: The generated report

card displayed on the monitor is

taken out as a printout (Fig. 1.7).

Fig. 1.6 Adding two numbers

3 + 7 = 10

is

1.David

2. SubjectsM. Marks O. Marks

3. Maths30

29

4. English30

27

5. Science30

25

6. Computer30

30

1.David

2. SubjectsM. Marks O. Marks

3. Maths30

29

4. English30

27

5. Science30

25

6. Computer30

30






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Playing games 1. Input: The player’s information given to the computer along with some keys

pressed to run the car.

2. Process: The speed and the direction of the player’s car is taken care of as per

the keys pressed.

3. Output: The effect of the keys pressed is seen in the form of animated pictures

and sound on the screen (Fig. 1.8).

Fig. 1.8 A child playing a computer game

A. Identify the input and output devices given below. Collect their pictures and make a project on it.

B. Suggest at least three more examples that can be compared with the IPO cycle.

A. Identify the input and output devices given below. Collect their pictures and make a project on it.

ACTIVITY






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Concept of Networking

De� nition of a computer networkThe word ‘network’ may be defined as a

collection of computers connected together

for the purpose of sharing information and

resources (Fig. 1.9). These interconnected

computers can be present within a local area

or may cross different cities or countries.

Computer networking is a core part of

the whole information technology field.

Computers can never communicate with

each other locally and remotely in the absence of computer networking. Just

imagine a bank or a corporate office without computer networking (Fig. 1.10)! How

difficult it would be for the employees to communicate and share the data.

In today’s world, networking is also used in bank transactions through ATMs, the

Internet and online ticketing and reservation, online shopping, etc.

Fig. 1.10 Computer networking

Fig. 1.9 Networking concept

Fig. 1.10 Computer networking

Counter 1

ReceiptReceipt Withdrawal

Counter 2 Counter 3






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Networking is a necessityThe need of networking arises due to the following reasons.

1. Limited resources: Instead of connecting a printer to all the computers separately,

you can connect it to the main network. In this way, every computer can share the

printer on a priority basis.

2. Desire to share information: Information is centralised. Thus, it is made available

to all the computers connected to a network.

3. Cost reduction: It reduces cost as an input device like a scanner and an output

device like a printer can be easily shared.

Parts of a computer networkThe different parts of a computer network are discussed here (Fig. 1.11).

1. Workstations: The individual computers connected to a network that share data

and information are called workstations or terminals. They can be compared to

clerks working together in a group, in a department, to do a specific job.

2. Server: The main computer in the networking environment that controls the

functioning of the entire network is called the server. It can be compared to a

manager of a company who manages all the work and coordinates well with the

various clerks.

Fig. 1.11 Parts of a computer network

Server Workstations

Cables






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3. Communication channels: These are used to connect the computers for the

purpose of sharing information. These communication channels can be either

cables, fibre optics, radio waves, or satellites (Fig. 1.12).

a. Internal modem b. External modem

Fig. 1.14 A router

Fig. 1.13 Types of modem

5. Router: It is an electronic

device that connects together

two or more networks and

directs the data between them

(Fig. 1.14).

4. Modem: It stands for Modulator Demodulator. A modem is an electronic device

which allows one computer to send information to another through standard

telephone wires and therefore cover long distances. It is required because,

computers are digital devices and the telephone system is analogue. The modem

converts data from digital to analogue and vice versa for effective transmission.

These days, three types of modem connections are available viz. cable, telephone

and wireless. They can be fitted inside the computer (internal modem) or placed

outside the computer (external modem) (Fig. 1.13).

Speed of a modem is calculated in bits per second (bps).

Fig. 1.12 Communication through satellite






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6. Bluetooth: It is a system for connecting electronic equipments such as mobile

phones and computers to each other and to the Internet using radio signals. To

use this technology a Bluetooth device is used. For example, these days you get

Bluetooth mobile phone headsets (Fig. 1.15).

Fig. 1.17 Local Area Network

Fig. 1.16 Personal Area Network

b. A Bluetooth mobile phone headseta. A Bluetooth logo

Types of NetworkFig. 1.15 Bluetooth

Personal Area NetworkWhen the computers and devices that belong

to the same user are interconnected over a

short range, it forms a Personal Area Network

or PAN (Fig. 1.16).

The communication channels in this case are

mainly Bluetooth and Wi-Fi devices.

Local Area Network (LAN) When the computers are

interconnected in the same office

building, school or home for

sharing information, then it forms

Local Area Network (LAN).

LAN connects computers over

a relatively short distance.

It generally uses cables as a

communication channel

(Fig. 1.17).

Internet

Router

SwitchSwitch

Web server

FaxPlotterFile

serverFile

serverFile

server






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Fig. 1.19 Wide Area Network

Metropolitan Area Network (MAN)When computers are interconnected to extend over an entire city, then it forms

Metropolitan Area Network or MAN (Fig. 1.18). For example, all the branches of a

company are interconnected using MAN within the same city. The cable operator

supplies cable television network using MAN.

The communication channels in this case are either cables or satellites.

Wide Area Network (WAN)When the computers are

interconnected for transmitting

information over a large geographical

area that may comprise a country, a

continent or even the whole world, it

forms a Wide Area Network or WAN

(Fig. 1.19). The Internet is the best

example of WAN.

The communication channels used

are mostly satellites.

Laptop

Commercial

Hospital

Municipal

Residential

Mobile phones

Fig. 1.18 Metropolitan Area Network






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Computer network: It is a network of computers, connected together for sharing information and resources.

Input: It is the raw data given to a computer.

Internet: It stands for Interconnected Network.

IPO cycle: It stands for the Input–Process–Output cycle.

LAN: It stands for Local Area Network.

MAN: It stands for Metropolitan Area Network.

Modem: It is a modulator and a de-modulator.

Output: It is the processed data generated and given to the outside world.

Process: It is the process of manipulating raw data using CPU.

Server: It is the main computer that controls the functioning of the entire network.

WAN: It stands for Wide Area Network.

Workstation: It refers to the individual computers in a computer network.

GLOSSARY

A. Try to find out which category of network is used in your lab.

B. Take the help of your teacher and prepare a PowerPoint presentation on types of computer network.

1. Computer is an electronic device capable of solving a problem by accepting data, performing operations on the data and giving the result.

2. An input is given to the computer using input devices like keyboard, mouse, scanner, etc.

3. Central Processing Unit is the computer’s processing device.

4. An output is given to the outside world using output devices like printer, monitor, plotter, etc.

5. The information flows from an input device to the processing device and then to an output device. This flow of information follows a cycle which is known as Input–Process–Output Cycle.

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A. Try to find out which category of network is used in your lab.

ACTIVITY






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